If $A$ and $B$ are not disjoint sets, then $n(A \cup B)$ is equal to
$n(A) + n(B)$
$n(A) + n(B) - n(A \cap B)$
$n(A) + n(B) + n(A \cap B)$
$n(A)\,n(B)$
Show that for any sets $\mathrm{A}$ and $\mathrm{B}$, $A=(A \cap B) \cup(A-B)$ and $A \cup(B-A)=(A \cup B).$
Let $A$ and $B$ be sets. If $A \cap X=B \cap X=\phi$ and $A \cup X=B \cup X$ for some set $X ,$ show that $A = B$
( Hints $A = A \cap (A \cup X),B = B \cap (B \cup X)$ and use Distributive law )
If $A$ and $B$ are sets, then $A \cap (B -A)$ is
Let $A = \{a, b, c\}, B = \{b, c, d\}, C = \{a, b, d, e\},$ then $A \cap (B \cup C)$ is
If $A=\{1,2,3,4\}, B=\{3,4,5,6\}, C=\{5,6,7,8\}$ and $D=\{7,8,9,10\} ;$ find
$B \cup D$